Sleeping cell detection in an open radio access network

Abstract

A method and apparatus for cell sleep state detection and recovery are provided. In the method and apparatus, an O-RAN network entity evaluates one or more resource utilization criteria indicative of whether a cell is in a sleep state to determine whether the one or more resource utilization criteria are met. The one or more resource utilization criteria are selected from a PUCCH criterion, a throughput criterion, a PRB utilization criterion, a PDCCH utilization criterion, a transmit or receive power criterion, a modulation and coding scheme criterion, a BLER criterion or a supplemental downlink criterion. The network entity determines whether the cell is in the sleep state based on whether at least one of the one or more resource utilization criteria are met and in response to determining that the cell is in a sleep state, causes the cell to exit the sleep state.

The invention claimed is: 
     
         1 . An Open Radio Access Network (O-RAN) network entity, comprising:
 a processor; and   a memory, coupled to the processor, having stored thereon executable instructions that, when executed by the processor, cause the processor to:
 receive one or more resource utilization criteria indicative of whether a cell is in a sleep state, wherein the one or more resource utilization criteria include a physical uplink control channel (PUCCH) criterion; 
 evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the PUUCH criterion is met, including:
 receive a number of resource elements or physical resource blocks (PRBs) used by user equipment in the cell; 
 determine whether the number of resource elements or PRBs is less than a threshold; and 
 in response to determining that the number of resource elements or PRBs is less than the threshold, determine that the PUCCH criterion is met; and 
 
 in response to determining that the PUCCH criterion is met, determine that the one or more resource utilization criteria are met; 
 
 determine that the cell is in the sleep state based on the one or more resource utilization criteria being met; and 
 in response to determining that the cell is in a sleep state, cause the cell to exit the sleep state. 
   
     
     
         2 . The O-RAN network entity of  claim 1 , wherein the threshold is a function of the number of resource elements or PRBs used by user equipment in one or more neighboring cells. 
     
     
         3 . The O-RAN network entity of  claim 1 , wherein:
 the executable instructions cause the processor to determine whether the PUCCH criterion is met, including:
 track, over a period of time, the number of resource elements or physical resource blocks (PRBs) used by user equipment in the cell; 
 determine whether that a change in the number of resource elements or PRBs over the period of time is less than a second threshold; and 
 in response to determining that the change in the number of resource elements or PRBs over the period of time is less than the second threshold, determine that the PUCCH criterion is met. 
   
     
     
         4 . The O-RAN network entity of  claim 1 , wherein:
 the one or more resource utilization criteria include a transmit or receive power criterion, and   the executable instructions cause the processor to evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the transmit or receive power criterion is met, including:
 determine a transmit power used by a next generation NodeB (gNB) of the cell; 
 determine whether the transmit power used by the gNB is a lowest transmit power setting available to the gNB; and 
 in response to determining that the transmit power used by the gNB is the lowest transmit power setting available to the gNB, determine that the transmit or receive power criterion is met; and 
 
 in response to determining that the transmit or receive power criterion is met, determine that the one or more resource utilization criteria are met. 
   
     
     
         5 . The O-RAN network entity of  claim 1 , wherein:
 the one or more resource utilization criteria include a modulation and coding scheme criterion, and   the executable instructions cause the processor to evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the modulation and coding scheme criterion is met, including:
 determine a modulation and coding scheme used by a next generation NodeB (gNB) of the cell; 
 determine whether the modulation and coding scheme used by the gNB is a least robust or least error-resilient modulation and coding scheme available to the gNB; and 
 in response to determining that the modulation and coding scheme used by the gNB is the least robust or least error-resilient modulation and coding scheme available to the gNB, determine that the modulation and coding scheme criterion is met; and 
 
 in response to determining that the modulation and coding scheme criterion is met, determine that the one or more resource utilization criteria are met. 
   
     
     
         6 . The O-RAN network entity of  claim 1 , wherein:
 the one or more resource utilization criteria include a modulation and coding scheme criterion, and   the executable instructions cause the processor to evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the modulation and coding scheme criterion is met, including:
 track, over a period of time, a modulation and coding scheme used by a next generation NodeB (gNB) of the cell; 
 determine whether the modulation and coding scheme used by the gNB has remained the same without change over the period of time; and 
 in response to determining that the modulation and coding scheme used by the gNB has remained the same without change over the period of time, determine that the modulation and coding scheme criterion is met; and 
 
 in response to determining that the modulation and coding scheme criterion is met, determine that the one or more resource utilization criteria are met. 
   
     
     
         7 . A method, comprising:
 receiving one or more resource utilization criteria indicative of whether a cell is in a sleep state, wherein the one or more resource utilization criteria include a modulation and coding scheme criterion:   evaluating the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determining whether the modulation and coding scheme criterion is met, including:
 determining a modulation and coding scheme used by a next generation NodeB (gNB) of the cell; 
 determining whether the modulation and coding scheme used by the gNB is a least robust or least error-resilient modulation and coding scheme available to the gNB; and 
 in response to determining that the modulation and coding scheme used by the gNB is the least robust or least error-resilient modulation and coding scheme available to the gNB, determining that the modulation and coding scheme criterion is met; and 
 
 in response to determining that the modulation and coding scheme criterion is met, determine that the one or more resource utilization criteria are met; 
   determining that the cell is in the sleep state based on the one or more resource utilization criteria being met; and   in response to determining that the cell is in a sleep state, causing the cell to exit the sleep state.   
     
     
         8 . The method of  claim 7 , wherein:
 the one or more resource utilization criteria include a physical uplink control channel (PUCCH) criterion, and   wherein evaluating the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met includes:
 determining whether the PUCCH criterion is met, including:
 receiving a number of resource elements or physical resource blocks (PRBs) used by user equipment in the cell; 
 determining whether the number of resource elements or PRBs is less than a threshold; and 
 in response to determining that the number of resource elements or PRBs is less than the threshold, determining that the PUCCH criterion is met; and 
 
 in response to determining that the PUCCH criterion is met, determining that the one or more resource utilization criteria are met. 
   
     
     
         9 . The method of  claim 8 , wherein the threshold is a function of the number of resource elements or PRBs used by user equipment in one or more neighboring cells. 
     
     
         10 . The method of  claim 7 , wherein:
 the one or more resource utilization criteria include a physical uplink control channel (PUCCH) criterion, and   wherein evaluating the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met includes:
 determining whether the PUCCH criterion is met, including:
 tracking, over a period of time, a number of resource elements or physical resource blocks (PRBs) used by user equipment in the cell; 
 determining whether a change in the number of resource elements or PRBs over the period of time is less than a threshold; and 
 in response to determining that the change in the number of resource elements or PRBs over the period of time is less than the threshold, determining that the PUCCH criterion is met; and 
 
 in response to determining that the PUCCH criterion is met, determining that the one or more resource utilization criteria are met. 
   
     
     
         11 . The method of  claim 7 , wherein:
 the one or more resource utilization criteria include a transmit or receive power criterion, and   wherein evaluating the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met includes:
 determining whether the transmit or receive power criterion is met, including:
 determining a transmit power used by a next generation NodeB (gNB) of the cell; 
 determining whether the transmit power used by the gNB is a lowest transmit power setting available to the gNB; and 
 in response to determining that the transmit power used by the gNB is the lowest transmit power setting available to the gNB, determining that the transmit or receive power criterion is met; and 
 
 in response to determining that the PUCCH criterion is met, determining that the one or more resource utilization criteria are met. 
   
     
     
         12 . The method of  claim 7 , wherein:
 wherein determining whether the modulation and coding scheme criterion is met includes:
 tracking, over a period of time, a modulation and coding scheme used by a next generation NodeB (gNB) of the cell; 
 determining whether the modulation and coding scheme used by the gNB has remained the same without change over the period of time; and 
 in response to determining that the modulation and coding scheme used by the gNB has remained the same without change over the period of time, determining that the modulation and coding scheme criterion is met. 
   
     
     
         13 . An Open Radio Access Network (O-RAN) network entity, comprising:
 a processor configured to:
 receive one or more resource utilization criteria indicative of whether a cell is in a sleep state, wherein the one or more resource utilization criteria include a transmit or receive power criterion: 
 evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the transmit or receive power criterion is met, including:
 determine a transmit power used by a next generation NodeB (gNB) of the cell; 
 determine whether the transmit power used by the gNB is a lowest transmit power setting available to the gNB; and 
 in response to determining that the transmit power used by the gNB is the lowest transmit power setting available to the gNB, determine that the transmit or receive power criterion is met; and 
 
 in response to determining that the transmit or receive power criterion is met, determine that the one or more resource utilization criteria are met; 
 
 determine that the cell is in the sleep state based on the one or more resource utilization criteria being met; and 
   a networking device configured to, in response to determining that the cell is in a sleep state, output a command to cause the cell to exit the sleep state.   
     
     
         14 . The O-RAN network entity of  claim 13 , wherein:
 the one or more resource utilization criteria include a physical uplink control channel (PUCCH) criterion, and   the processor is configured to evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the PUCCH criterion is met, including:
 receive a number of resource elements or physical resource blocks (PRBs) used by user equipment in the cell; 
 determine whether the number of resource elements or PRBs is less than a threshold; and 
 in response to determining that the number of resource elements or PRBs is less than the threshold, determine that the PUCCH criterion is met; and 
 
 in response to determining that the PUCCH criterion is met, determine that the one or more resource utilization criteria are met. 
   
     
     
         15 . The O-RAN network entity of  claim 14 , wherein the threshold is a function of the number of resource elements or PRBs used by user equipment in one or more neighboring cells. 
     
     
         16 . The O-RAN network entity of  claim 13 , wherein:
 the one or more resource utilization criteria include a physical uplink control channel (PUCCH) criterion, and   the processor is configured to evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the PUCCH criterion is met, including:
 track, over a period of time, a number of resource elements or physical resource blocks (PRBs) used by user equipment in the cell; 
 determine whether a change in the number of resource elements or PRBs over the period of time is less than a threshold; and 
 in response to determining that the change in the number of resource elements or PRBs over the period of time is less than the threshold, determine that the PUCCH criterion is met; and 
 
 in response to determining that the PUCCH criterion is met, determine that the one or more resource utilization criteria are met. 
   
     
     
         17 . The O-RAN network entity of  claim 13 , wherein:
 the one or more resource utilization criteria include a modulation and coding scheme criterion, and   the processor is configured to evaluate the one or more resource utilization criteria to determine whether the one or more resource utilization criteria are met, including:
 determine whether the modulation and coding scheme criterion is met, including:
 determine a modulation and coding scheme used by a next generation NodeB (gNB) of the cell; 
 determine whether the modulation and coding scheme used by the gNB is a least robust or least error-resilient modulation and coding scheme available to the gNB; and 
 in response to determining that the modulation and coding scheme used by the gNB is the least robust or least error-resilient modulation and coding scheme available to the gNB, determine that the modulation and coding scheme criterion is met; and 
 
 in response to determining that the modulation and coding scheme criterion is met, determine that the one or more resource utilization criteria are met.